A spectroscopic study of the superplasticizer effect on early cement hydration
- Organic/inorganic mixtures were prepared from ordinary Portland cement (OPC), water (w/c 0.22), a fluorescent dye in aqueous solution (stable at alkaline pH; BAM-I), and two different comb shape polycarboxylates (PCEs), i.e., high charge (PCE-HC) and low charge (PCE-LC), respectively. Rheological and calorimetric measurements were performed prior to optical studies in order to select PCE concentrations. Absorption and fluorescence spectroscopy of the system OPC + BAM-I (CBAM-I) revealed maxima of dye BAM-I located at 645 nm and 663 nm, respectively. In presence of PCE-HC and PCE-LC, these mixtures displayed a small red shift in reflectance and a faster decrease in intensity compared to studies with CBAM-I; however, only slight differences were observed between the different PCEs. With time, all systems exhibited a decrease in intensity of BAM-I in absorption/reflectance and emission. This could be caused by dye adsorption and possibly decomposition when in contact with cementOrganic/inorganic mixtures were prepared from ordinary Portland cement (OPC), water (w/c 0.22), a fluorescent dye in aqueous solution (stable at alkaline pH; BAM-I), and two different comb shape polycarboxylates (PCEs), i.e., high charge (PCE-HC) and low charge (PCE-LC), respectively. Rheological and calorimetric measurements were performed prior to optical studies in order to select PCE concentrations. Absorption and fluorescence spectroscopy of the system OPC + BAM-I (CBAM-I) revealed maxima of dye BAM-I located at 645 nm and 663 nm, respectively. In presence of PCE-HC and PCE-LC, these mixtures displayed a small red shift in reflectance and a faster decrease in intensity compared to studies with CBAM-I; however, only slight differences were observed between the different PCEs. With time, all systems exhibited a decrease in intensity of BAM-I in absorption/reflectance and emission. This could be caused by dye adsorption and possibly decomposition when in contact with cement particles or hydration products.…
Autor*innen: | Alejandra Ramirez Caro, Berta Mota, E. Artemeva, Jutta Pauli, Wolfram SchmidtORCiD, Ute Resch-GengerORCiD |
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Dokumenttyp: | Beitrag zu einem Tagungsband |
Veröffentlichungsform: | Graue Literatur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | Tagungsband der 20. Internationalen Baustofftagung ibausil |
Jahr der Erstveröffentlichung: | 2018 |
Organisationseinheit der BAM: | 1 Analytische Chemie; Referenzmaterialien |
1 Analytische Chemie; Referenzmaterialien / 1.2 Biophotonik | |
7 Bauwerkssicherheit | |
7 Bauwerkssicherheit / 7.4 Baustofftechnologie | |
Verlag: | F.A. Finger-Institut für Baustoffkunde |
Verlagsort: | Weimar |
Jahrgang/Band: | 20 |
Erste Seite: | 1 |
Letzte Seite: | 6 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten | |
Freie Schlagwörter: | Cement hydration; Dyes; Optical spectroscopie |
Themenfelder/Aktivitätsfelder der BAM: | Material |
Umwelt | |
Umwelt / Sensorik | |
Veranstaltung: | 20. Internationale Baustofftagung |
Veranstaltungsort: | Weimar, Germany |
Beginndatum der Veranstaltung: | 12.09.2018 |
Enddatum der Veranstaltung: | 14.09.2018 |
ISBN: | 978-3-00-059950-7 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 24.10.2018 |
Referierte Publikation: | Nein |